Cable tray connector



Jan. 28, 1964 w, McLEQD 3,119,472

CABLE TRAY CONNECTOR Filed Feb. 4, 1.960

INVENTOR.

United States Patent 3,119,472 CABLE TRAY CONNECTOR Donald Ward McLeod, Don Mills, Ontario, Canada, assignor to Burndy Corporation, a corporation of New York Filed Feb. 4, 1960, Ser. No. 6,643 1 Claim. (Cl. 189-35) This invention relates to connecting means. More particularly, it is concerned with means for detachably connecting together, in alignment and end abutted relation, bar length; e.g. sectional lengths of trays or channels;

It is common practice in the construction industry to run power or central cables and piping in trays. The trays serve the purpose of grouping, supporting and protecting the cables, and should provide a continuous ground circuit. These trays are generally supplied in a limited range of lengths and shapes, e.g. straight runs, bends, T junctions, etc. which must subsequently be joined when installed. Furthermore, when installed in the field, it often becomes necessary to cut the tray to a desired length and join together the various stock pieces. The tools and time available for installation or maintenance may be limited. Some trays of the prior art require accurately located square holes to be made when joining field-cutto-length sections. Many trays have elaborate hinges or special plates which must be joined by inserting an element from above the trays and thus prevent a close-tothe-ceiling installation. A common field expedient is to avoid altogether the connecting means supplied with the trays and simply bolt a plate across the joint with at least four bolts. The plate, however, is not a standard item, adds considerably to the total tray weight, and requires the use of two Wrenches to tighten the bolts, one inside and one outside the tray. Some tray joints or connectors also have sharp edges inside which may injure the insulation of the cable.

An object of this invention is to provide a connector which may be installed close to the ceiling and requires but one wrench on the outside of the tray.

An additional object is to provide a connector that uses only one special or non-standard part, and requires only simple holes to be made for field installation of cut-tole-ngth pieces.

-A further object is to provide a connector which makes a positive electrical connection at the coupling point to insure a. continuous ground circuit.

A feature of this invention is a connector for detachably connecting two bar lengths or the like comprising at least a U shaped member having two side elements and a bottom element connecting one end of each side element.

These and other objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a tray connecting means embodying one form of this invention;

FIG. 2 is a top view of the connector of FIG. 1;

FIG. 3 is a front view of the connector of FIG. 1;

FIG. 4 is a fragmentary perspective view of two trays joined by the connector of this invention illustrated in FIG. 1;

FIG. 5 is a perspective view of an alternate embodiment of a connecting means in accordance with the principles of this invention;

FIG. 6 is a perspective view of a modification of the embodiment of 'FIG. 5; and

FIG. 7 is a perspective view of still another embodiment of the connecting means of this invention.

Referring to FIGS. 1, 2, and 3 of the drawing, reference character 1 indicates the connector of this inven- 3,119,472 Fatented Jan. 28, 1964 tion, having a first pair of side elements 3 and 5, connected by component 11, and a second pair of side elements 7 and 9 connected by component 13. Side elements 5 and 9 are connected by component 15. Elements 3 and 5 are at a slight angle to each other, the apex being in the direction of component 11. Similarly, elements 7 and 9 are at a slight angle, the apex being in the direction of component 13. Elements 3 and 7 are threaded, as at 17 and '19 respectively, and receive nuts 21 and 23 respectively. The connector rnight be described as a U bolt.

The double U bolt connector of FIG. 1 is used to connect trays in end abutted relation as illustrated in FIG. 4, wherein 71 and 73 indicate lengths of tray having side rails 75, 77, 79, and 8 1. A pair of holes is made in each rail adjacent the ends to be abutted; the distance between each pair of holes being substantially equal to the length of components 15 and the distance between each hole and the end of each rail is preferably equal to one half the length of components 1 1 and 13. The bolt 1, elements 3 and 7 leading, is inserted through one pair of holes from outside the tray and then passed through the other pair of holes, so that threaded ends 17 and '10 and component 15 are outside the joined trays, while components 11 and 13 are inside the trays. Nuts 21 and 23 are attached to ends 17 and 19 and tightened by means of a single wrench from outside the tray. No operations are performed inside or above the tray, permitting the tray to be installed close to the ceiling, if so desired. Tightening the nuts, draws the rail ends tightly together due to the angle formed by the side elements of the bolt. The same effect can be produced by providing a radius between elements 11 and 5, and 9 and 13. This radius would function to hring the rail ends tightly together, as the radius is disposed within the holes. A good electrical contact, yielding a continuous ground, is obtained thereby.

FIG. 5 illustrates an alternate embodiment of the invention. This. embodiment 500 has side elements 503 and 505 connected by an element 511. Elements 503 and 505 are at a slight angle to each other, the apex being in the direction of element 511. Side element 505 has a lug 515 connected at right angles to its free end. Side element 503 is threaded at 517 to take a nut.

Connector 500 is mounted by inserting the threaded end 507 through a hole adjacent one end from outside the tray, and back through the hole adjacent the other rail end, leaving the lug and the threaded end on the outside of the tray. Tightening a nut on end 517 clamps both rail ends. in place and tightly together due to the angle between 503 and 505.

FIG. 6 illustrated a modification 600 of the embodiment of FIG. 5. A hole 621 is made in lug 615 which permits the connector to be bolted, wired or otherwise secured to the rail in a factory partially-preassembly.

FIG. 7 illustrates still another embodiment of the invention. This embodiment has side elements 703 and 705 connected by element 711. Elements 703 and 705 are at a slight angle to each other, the apex being in the direction of element 711. Side elements 703 and 705 are threaded at 717 and 72.1 respectively to take a nut. The connector 700 is inserted in one rail hole, and out the other rail hole, with the threaded ends outside the tray. Nuts are tightened on the ends 717 and 721 clamping both raril ends in place. Since elements 703 and 705 are at an angle to each other, tightening the nuts draws the rail ends tightly together.

The connectors 5'00, 600, and 700 may be used singly to connect abut-ting rails, or in pairs.

The connectors may all be formed by any of the standard manufacturing processes, e.g. formed of wire stock, cast, forged, etc. They may be made of circular crosssection or of fiat cross-section. More particularly, only certain portions may be formed with a flat cross-section.

For example, components '11 and 13, and/or 15 may be flat to minimize their'protrusion in the inside or on the outside of the tray.

The invention has thus been described, but it is desired to'be understood that it is not confined tothe particular forms or usage shown and described. The same being merely illustrative, and that the invention-may be carried out inother Ways without-departing from the spirit of theinwention, and therefore, the right is broadly claimed to employ all equivalentinstrumentalities coming within the scope of the appendant claim, 'and'by means of which objects. of the'invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to obtain these objects andw'accomlplish these results.

1 claim:

A connector comprising: a first pair of uniformly spaced apart side members; a pair of uniformly spaced apart end members'each joined to an end of one of said (3. side members respectively and disposed at an obtuse angle thereto; a second pair of uniformly spaced apart side members each coplanar with one of said side members of said first pair, and each joined to the other end of one of said end members. respectively and disposed at said obtuse angle thereto; and a connecting link joining the free ends of said second pair of side members and disrposed at right anglesthereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,164,331 Briggs Dec. 14, 1915 1,824,797 Zabriskie Sept. 29, 1931 2,121,432 Jacobson June 21, 1938 2,570,365 Michael et al Oct.9, 1951 2,860,742 -Waters et a1 Nov. 18, 1958 FOREIGN PATENTS 619,049 Great Britain Mar. 3, 1949 

